Mould for monocrystalline casting

Abstract

The invention relates to the field of monocrystalline casting, and more specifically to a mold (1) for monocrystalline casting, and also to fabricating and using the mold. In particular, the mold (1) presents a mold cavity (7) comprising a first volume (7a), a second volume (7b) and a grain duct (4). The second volume (7b) is situated on the first volume (7a), being in communication therewith, and includes at least one horizontal projection relative to the first volume (7a). The grain duct (4) has a bottom end (4a) connected to the first volume (7a) and a top end (7b) adjacent to said horizontal projection of the second volume (7b). The mold (1) also has a separator member (11) interposed between the second volume (7b) of the mold cavity (7) and the top end (4b) of the grain duct (4).

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates to the field of casting, and more particularly to a model for lost-pattern casting, and also to methods of fabricating shell molds and of casting using such a model.[0002]In the description below, the terms “top”, “bottom”, “horizontal”, and “vertical” are defined relative to the normal orientation of such a mold while metal is being cast into it.[0003]So-called “lost-wax” or “lost-pattern” casting methods have been known since antiquity. They are particularly suitable for producing metal parts of complex shape. Thus, lost-pattern casting is used in particular for producing turbomachine blades.[0004]In lost-pattern casting, the first step is normally to make a model out of a material having a melting temperature that is comparatively low, e.g. a wax or a resin. The model is itself coated in a refractory material in order to from a mold, in particular a mold of the shell mold type. After the model of the material has been...

AI Technical Summary

Benefits of technology

The present invention proposes a way to make parts with large lateral projections more efficiently by using a special mold. This mold prevents the metal material from solidifying in the horizontal projection, making it easier to separate the metal branch from the rest of the raw casting. This improves the process of molding parts with complex shapes, and makes them easier to treat afterward.

Problems solved by technology

An awkward shape in the mold cavity can constitute an obstacle to such directional solidification.

Such a sudden change of direction can give rise to defects, and in particular to unwanted grains, in the proximity of the projection.

Nevertheless, a drawback of such a grain duct is that it makes the mold more difficult to knock out, and above all the metal branches that result from the solidification of the metal material in the grain duct subsequently need to be removed from the raw casting, thereby adding finishing-off steps that are complicated and expensive.

Images